package com.halopay.common.utils;

import java.math.BigDecimal;
import java.util.Random;

/**
 * @author mingpingqiang on 2019/1/19/17:09
 * Created by mingpingqiang on 2019/1/19/17:09
 */
public class RedPackage {
/**
 *
 * @param money 发红包的金额
 * @param num 人数
 * @return
 * @throws RuntimeException
 */
        public static BigDecimal[] red(BigDecimal money,int num) throws RuntimeException {
            if (money.doubleValue() < num * 0.01) {
                throw new RuntimeException("金额不对....");
            }

            Random random = new Random();
            //使用分 进行计算金额
            int allMoney = money.multiply(BigDecimal.valueOf(100)).intValue();

            int count = 0; //存储所有人的随机点数和
            double[] perCount = new double[num];//存储每一个人的随机点数

            BigDecimal[] perMoney = new BigDecimal[num]; //存储每一个人的红包金额

            // 给每一个人分配一个随机数
            for (int i = 0; i < perCount.length; i++) {
                int r = random.nextInt((num) * 99) + 1;
                count += r;
                perCount[i] = r;
            }


            int c = 0;
            //分配红包金额
            for (int i = 0; i < perCount.length; i++) {
                Double x = new Double(perCount[i] / count);
                int m = (int) Math.floor(x * allMoney);
                if (m == 0) {
                    m = 1;
                }
                c += m;

                if (i < perCount.length - 1) {
                    perMoney[i] = (new BigDecimal(m).divide(new BigDecimal(100)));
                } else {
                    perMoney[i] = (new BigDecimal(allMoney - c + m).divide(new BigDecimal(100)));
                }
            }

            return perMoney;
        }
}
